Wireless communication systems use base stations to provide wireless communication services to wireless communication devices which are present in the base stations' coverage area. Wireless communication devices establish communication sessions with the base stations through transmission and reception of radio frequency waves. This approach allows the wireless communication devices to maintain communications even though they are mobile. Providing wireless communication coverage over a large geographical area usually requires multiple base stations because the radio frequency waves have finite geographic ranges and because the base stations typically have fixed physical locations.
In order to allow wireless communication devices to have freedom to move about a geographic area without experiencing communication interruption, the base stations and their associated control systems must be able to accommodate the transition of a communication session from one base station to another. In these handoff processes, a wireless communication device communicating with one base station can transition out of the coverage area of that base station and into the coverage area of another base station without losing continuity of the communications. Coordination is required between the base stations, their associated control equipment, and the wireless device in order to accomplish this handoff. The specific steps necessary to complete a handoff vary depending on many factors including whether the two base stations involved in the transition are operating on the same frequency band or on different frequency bands.
Overview
A wireless communication system includes a first base station and a second base station. The first base station transmits wireless communication signals over a first frequency band and over a second frequency band. The second base station transmits wireless communication signals over the first frequency band and processes loading of the first frequency band of the first base station to determine a user priority between the first frequency band of the first base station and the second frequency band of the first base station. The second base station also transmits an indication of the user priority to wireless communication devices. The wireless communication devices select between the first frequency band and the second frequency band based on the user priority. The first base station also determines a distance between the first base station and a wireless communication device utilizing the second frequency band of the first base station and determines a velocity of the wireless communication device. If the distance exceeds a first threshold or the velocity exceeds a second threshold, the first base station transmits a message to the wireless communication device.